Week 6 (lecture and discussion mixture) Flashcards
Fish exhibit ________ including __________
alternative reproductive tactics (ARTs),
sequential
hermaphroditism
Protogynous _____________ → Blue headed wrasse
(female to male)
Protandrous _____________ → Clownfish
(male to female)
Serial______________ → Maori coral gobies
bidirectional sex change
What control the diverse sexual phenotypes in fish
Hormonal control is involved
____________ dominant theory for plasticity of reproductive
systems
Size advantage model (SAM):
Timing of sex change maximizes _______________
expected lifetime reproductive sucess and fitness
What are the size advantages of males and females
○ Older = bigger
○ Male → female: Big females can make lots of eggs
○ Female → male: Big males defend better
What are some of the forms of ART
- two distinct phenotypes within a sex that utilize different behavioral tactics to acquire a mate
- singular unidirectional adult sex change and within sex morph changes
- singular, unidirectional sex change
- singular unidirectional intersexual male morph change
- serial back and forth sex change
- bisexual simultaneous hermaphrodite
- serial back and forth shift by males between reproductive and non reproductive state
The California singing fish is considered a sexually ________ as there are ___________
polymorphic
type I and type II males and females
_____________ are responsible for defending the nest and caring for eggs. Have a larger swim bladder and vocal muscles
type I males
________ responsible for reproduction. They have larger gonads relative to body size
Type II males
________ responsible for laying eggs. Have larger gonad relative to body size
Females
______ diverge across the sexes as the size and morphology of the gonads and vocal organs is completely different
somatic characteristics
______________ are the three kinds of sequential hemaprhodizm
- protgynous
- protoandrous
- serial bidriectional
__________ drives the evolution of protogynous sex change. because
Male size
Larger males use aggressive defensive to monopolize matings with females and thus small males are at a disadvantage
What is the dominant driving force of protandry
female size as there is a positive relationship between female fecundity
protandry is less widespread and is usually associated with monogomy or random mating systems without male territorial defense or competition.
monogamy
clownish show protandry as
a monogous pair of clownfish share a shelter with immature subordinates. Then the males will turn into a female
serial bidirectional sex change occurs so that any 2 fish can form a _______
heterosexual breeding pair. this occurs in animals where its is hard to come across a mate.
In many sequential hermaphrodites, recognizable
tissues of both sexes are present in the gonad prior to the sex change
A transitional bluehead wrasse Gonad shows degenerating _______________This is because of protogynous sex change.
oocytes and proliferation of spermatocytes,
protandrous fish would show ________
developing ovarian tissue
Goby fish that exhibit bidirectional sex change have share
ovotestis
__________ have an ovarian portion with vitellogenic and previtellogenic oocytes plus regressed testicular portion
Female ovotestis
_____________ have testitcular tissue in active spermatogenic dominates the gonad, and a small ovarian portion contain early stage oocytes and accessory gonadal structures
male ovotestis
_________ is key for sex transition in fish
aromatase
Sex shift occurs with shift in sex hormones
and genes
○ More E2 + female-related genes = ____________
○ More 11-ketoT + male related genes = __________
●
female
phenotype
male
phenotype
Aromatase present: T → E2
○ E2 upregulates genes that create FSH + E2
○ Activate female pathway genes
No aromatase present: T → 11-ketoT
○ 11-ketoT acts on genes to shut down aromatase
production and promote continued actions of
androgens
○ Promotes male pathway
___________genes to shut down aromatase
production and promote continued actions of
androgens
○ 11-ketoT acts on
Diversity in behavioral and reproductive systems have a key hormonal
dependence
○ 11keto-T vs E2
Redirection of gonadal fate begins with expression of sex maintenence genes
○ Female-related genes upregulated → fish becomes female
○ Male-related genes upregulated → fish becomes male
_______ is involved in sex change
cortiosol
______ genes maintain sexual fate in fishes by promoting either ______________
antagonist sex specific genes
estrogenic or androgenic environment
In female CYP1919 expression generates _____________ and unregulated estrogen levels
amromatse
In males CYP1919 expression surpasses _______ and _____ prevails to support testicular function
aromatase
androgen
_________ involves motivation to approach and remain in close proximity with
a conspecific (brings individuals together)
○ Examples: Pair-bonding, Parental care, Grooming
●
Affiliation:
Neuropeptides:
_____________
■ Physiological function: contract smooth muscle
○ Oxytocin (OXY)
Neuropeptide:
_______________
■ Physiological function: water reabsorption in kidneys
Arginine-Vasopressin (AVP)
Milk Let-down Reflex
Suckling stimulates mechanoreceptors
2. Ascending neurons send information to brain
3. Magnocellular neurons in supraoptic nucleus (SON) and
paraventricular nucleus (PVN) are stimulated
4. Neurons project to the posterior pituitary and release OXY
into capillaries → enter circulation
5. OXY acts on oxytocin receptors on myoepithelial cells
(smooth muscle surrounding alveoli @ mammary gland)
6. Increase in intracellular Ca2+ contracts myoepithelium
7. Milk in alveoli is pushed out through mammary ducts
________ can inhibit the oxytocin response in mammary glands while _____ can excite it
stress
sounds of the baby crying
Ferguson’s Reflex
- Baby pushing on cervix stimulates mechanoreceptors
- Ascending neurons send information to brain
- Magnocellular neurons in supraoptic nucleus (SON) and
paraventricular nucleus (PVN) are stimulated - Neurons project to the posterior pituitary and release OXY into
capillaries → enter circulation - OXY acts on oxytocin receptors on myometrium (smooth muscle
surrounding uterus) - Increase in intracellular Ca2+ contracts myometrium
- Labor occurs
________ unregulates oxytocin receptors
estrogens
Pheripheral receptors that are unregulated by estrogen
Periphery:
- Mammary glands (Milk let-down)
○ 2. Myometrium (Ferguson’s reflex)
Central receptors that are unregulated by estrogen
1. PVN ○ 2. AMYG - amygdala ○ 3. BNST - bed nucleus of stria terminalis ○ 4. MPOA - medial preoptic area ○ 5. LS
● Female rats that showed high amounts of
maternal care also showed high ______________
OXY
receptor levels in AMYG, BNST, and MPOA
Estrogen and progesterone cause
upregulation of
OXY mRNA in
PVN, SON, BNST, and MPOA
● OXY is increased even more
during ___________
birth and lactation
In sheep there is strong evidence that links increases in synthesis and particularly release of oxytocin in the brain to the induction and maintenance of __________________
maternal behavior
In moms:
___________levels in pregnancy positively correlates to the level of intrest in the infant and increase rates of nursing and grooming of offspring
oxytocin levels
In dads:
Treatment with oxytocin’s showed more support of
learning and exploration and decrease in hostility toward infants
oxytocin is associated with __________, positive communication sequences. Stimulatory contact and play
parent positive engagement and coordination of positive behaviors
Monogamy vs polygamy in voles
● Prairie Voles: monogamous (pair-bonding)
● Meadow Voles: polygamous (promiscuous
Monogamous prairie voles have more __________________
OXY
and AVP receptors in reward areas of brain
○ Nucleus accumbens (NAcc)
○ Ventral pallidum (VP)
The reward areas of brain are
○ Nucleus accumbens (NAcc)
○ Ventral pallidum (VP)
This is because receptors in reward areas correspond top a desire for _______________
○ Nucleus accumbens (NAcc)
○ Ventral pallidum (VP)
When you Block OXY receptors in Nacc →
block preference
for mate
when you Block AVP receptors in VP →
block preference for mate
when you Inject genes of AVP receptor into VP
make them monogamous
OXY strengthens the bond between mates and
Also seen in parent to child relationship
